VLT/VIMOS integral field spectroscopy of luminous and ultraluminous infrared galaxies: 2D kinematic properties

We present and discuss the 2D kinematic properties of the ionized gas (Halpha) in a sample of 38 local (ultra) luminous infrared galaxies [(U)LIRGs] (31 LIRGs and 7 ULIRGs) observed with VIMOS at the VLT using integral field spectroscopy. This sample covers well the less studied LIRG luminosity range and includes isolated disks, interacting systems, and mergers. The majority of the galaxies have two main kinematically distinct components. One component (i.e., narrow or systemic) extends over the whole line-emitting region and is characterized by small to intermediate velocity dispersions (i.e., sigma from 30 to 160 km s^-1). It traces the overall velocity field. The second component (broad) has in general a larger velocity dispersion (up to 320 km s^-1), mainly found in the inner regions and generally blueshifted with respect to the systemic component. Most of the objects (76%) are dominated by rotation, more relevant in LIRGs than in ULIRGs. Isolated disks, interacting galaxies, and merging systems define a sequence of increasing mean velocity dispersion, and decreasing velocity field amplitude.The LIRGs classified as isolated disks have similar velocity amplitudes but larger mean velocity dispersions (44 vs. 24 km s^-1) than local spirals, implying a larger turbulence and thicker disks. Interacting systems and mergers have values closer to those of low velocity dispersion ellipticals/lenticular galaxies (E/SOs). The (U)LIRGs classified as mergers have kinematic properties similar to those shown by the Lyman break analogs (LBAs). The dynamical masses range from \sim 0.04 m* to 1.4 m* (i.e., m* = 1.4x10^{11} Msun), with ULIRGs (M{dyn} sim 0.5 +/- 0.2 m*) being more massive than LIRGs by, on average, a factor of about 2. The mass ratio of individual pre-coalescence galaxies is <2.5 for most of the systems, confirming that most (U)LIRG mergers involve sub-m* galaxies of similar mass.Comment: 66 pages, 5 figures plus 45 figures in App. A; accepted for publication in A&

QSO2 outflow characterization using data obtained with OSIRIS at the Gran Telescopio Canarias

Ionized outflows are ubiquitous in non radio-loud obscured quasars (QSO2s) at different redshifts. We search for large-scale ionized outflows associated with six optically selected QSO2 (five non-radio-loud and one radio-loud) at $z\sim$ 0.2-0.5, targeting objects with extended radio structures. We have obtained OSIRIS/GTC optical long slit spectroscopy data for these six QSO2 with the slit located along the radio axis. We traced the gas kinematics with the [OIII]$\lambda$4959,5007 lines to investigate ionized outflows and characterize the dynamical state of the host galaxies. This second study has been complemented with previously published FORS2/VLT spectroscopic data of 13 more QSO2 at similar z. We identify ionized outflows in four out of the six QSO2 observed with the GTC. The outflows are spatially unresolved in two QSO2 and compact in a third (radial size of R=0.8$\pm$0.3 kpc). Of particular interest is the radio-quiet QSO2 SDSS 0741+3020 at z=0.47, associated with a giant $\sim$ 112 kpc nebula. An ionized outflow probably induced by the radio structures has been detected along the axis defined by the central $\sim$1\arcsec\ radio structure, extending up to at least $\sim$4 kpc from the active galactic nucleus (AGN). Turbulent gas ($\sigma\sim$130 km s$^{-1}$) has also been detected across the giant gas nebula up to $\sim$40 kpc from the AGN. This turbulence may have been induced by outflows triggered by the interaction between a so-far undetected large-scale radio source and the nebula. Regarding the dynamical state of the host galaxies, we find that the majority of the QSO2 show v/$\sigma<$ 1, implying that they are dominated by random motions (so-called dispersion-dominated systems). Most (17 of 19) fall in the area of the E/S0 galaxies in the dynamical diagram v/$\sigma$ versus $\sigma$. None are consistent with spiral or disk galaxies.Comment: 27 pages, 11+8 figures, accepted for publication in A&

Ionized gas outflows and global kinematics of low-z luminous star forming galaxies

We study the kinematic properties of the ambient ionized ISM and ionized gas outflows in a large and representative sample of local luminous and ultraluminous infrared galaxies (U/LIRGs) (58 systems, 75 galaxies), on the basis of integral field spectroscopy (IFS)-based high S/N integrated spectra at galactic and sub-galactic, i.e. star forming (SF) clumps, scales. Ambient ionized gas. The velocity dispersion of the ionized ISM in U/LIRGs ( ~ 70 kms-1) is larger than in lower luminosity local star forming galaxies ( ~ 25 kms-1). While for isolated disc LIRGs star formation appears to sustain turbulence, gravitational energy release associated to interactions and mergers plays an important role driving sigma in the U/LIRG range. We also find that the impact of an AGN in ULIRGs is strong, increasing sigma by a factor 1.5 on average. The observed weak dependency of sigma with SFR surface density for local U/LIRGs is in very good agreement with that measured in some high-z samples. Ionized outflows. The presence of ionized gas outflows in U/LIRGs seems universal based on the detection of a broad, usually blueshifted, Halpha line. AGNs in U/LIRGs are able to generate faster (x2) and more massive (x1.4) ionized gas outflows than pure starbursts. The derived ionized mass loading factors are in general below one, with only a few AGNs above this limit. Only a small fraction of the ionized material from low mass LIRGs (log(Mdyn/Msun) < 10.4) could reach the intergalactic medium, with more massive galaxies retaining the gas. The observed average outflow properties in U/LIRGs are similar to high-z galaxies of comparable SFR. In the bright SF clumps found in LIRGs, ionized gas outflows appear to be very common. For a given SFR surface density, outflows in LIRG clumps would be about one to two orders of magnitude less energetic than those launched by clumps in high-z SF galaxies.Comment: 36 pages, 20 figures, 6 tables. Accepted for publication in A&

Star-formation histories of local luminous infrared galaxies

We present the analysis of the integrated spectral energy distribution (SED) from the ultraviolet (UV) to the far-infrared and H$\alpha$ of a sample of 29 local systems and individual galaxies with infrared (IR) luminosities between 10^11 Lsun and 10^11.8 Lsun. We have combined new narrow-band H$\alpha$+[NII] and broad-band g, r optical imaging taken with the Nordic Optical Telescope (NOT), with archival GALEX, 2MASS, Spitzer, and Herschel data. The SEDs (photometry and integrated H$\alpha$ flux) have been fitted with a modified version of the MAGPHYS code using stellar population synthesis models for the UV-near-IR range and thermal emission models for the IR emission taking into account the energy balance between the absorbed and re-emitted radiation. From the SED fits we derive the star-formation histories (SFH) of these galaxies. For nearly half of them the star-formation rate appears to be approximately constant during the last few Gyrs. In the other half, the current star-formation rate seems to be enhanced by a factor of 3-20 with respect to that occured ~1 Gyr ago. Objects with constant SFH tend to be more massive than starbursts and they are compatible with the expected properties of a main-sequence (M-S) galaxy. Likewise, the derived SFHs show that all our objects were M-S galaxies ~1 Gyr ago with stellar masses between 10^10.1 and 10^11.5 Msun. We also derived from our fits the average extinction (A_v=0.6-3 mag) and the polycyclic aromatic hydrocarbons (PAH) luminosity to L(IR) ratio (0.03-0.16). We combined the A_v with the total IR and H$\alpha$ luminosities into a diagram which can be used to identify objects with rapidly changing (increasing or decreasing) SFR during the last 100 Myr.Comment: 16 pages + online material, accepted for publication in A&

Interactions between large-scale radio structures and gas in a sample of optically selected type 2 quasars

Context. The role of radio mode feedback in non radio-loud quasars needs to be explored in depth to determine its true importance. Its effects can be identified based on the evidence of interactions between the radio structures and the ambient ionised gas. Aims. We investigate this interaction in a sample of 13 optically selected type 2 quasars (QSO2) at z < 0.2 with the Very Large Array (VLA) FIRST Survey radio detections, none of which are radio-loud. The ranges of [OIII]λ5007 and monochromatic radio luminosities are log(L[OIII]/erg s−1 ) ∼ 42.08–42.79 and log(P1.4 GHz/erg s−1 Hz−1 ) ∼ 30.08−31.76. All of them show complex optical morphologies, with signs of distortion across tens of kpc due to mergers and interactions. Methods. We searched for evidence of interactions between the radio structures and the ionised gas by characterising and comparing their morphologies. The former was traced by narrow band Hα images obtained with the GTC 10.4 m Spanish telescope and the Osiris instrument. The latter is traced by VLA radio maps obtained with A and B configurations to achieve both high resolution and brightness sensitivity. Results. The radio luminosity has an active galatic nucleus (AGN) component in 11 our of 13 QSO2, which is spatially extended in our radio data in 9 of them (jets, lobes, or other). The relative contribution of the extended radio emission to the total P1.4 GHz is in most cases in the range from 30% to 90%. The maximum sizes are in the range of d R max of around a few to 500 kpc. The QSO2 undergoing interaction or merger events appear to be invariably associated with ionised gas spread over large spatial scales with maximum distances from the AGN in the range rmax ∼ 12−90 kpc. The morphology of the ionised gas at <30 kpc is strongly influenced by AGN related processes. Evidence for radio-gas interactions exist in 10 out of 13 QSO2; that is, in all but one with confirmed AGN radio components. The interactions are identified across different spatial scales, from the nuclear narrow line region up to tens of kpc. Conclusions. Although this sample cannot be considered representative of the general population of QSO2, it supports the idea that large-scale low to modest power radio sources can exist in radio-quiet QSO2, which can provide a source of feedback on scales of the spheroidal component of galaxies and well into the circumgalactic medium, in systems where radiative mode feedback is expected to dominate

Distinguishing disks from mergers: Tracing the kinematic asymmetries in local (U)LIRGs using kinemetry-based criteria

Context. The kinematic characterization of different galaxy populations is a key observational input for distinguishing between different galaxy evolutionary scenarios because it helps to determine the number ratio of rotating disks to mergers at different cosmic epochs. Local (ultra) luminous infrared galaxies ((U)LIRGs) cover similar range of star formation rates (SFR) as normal high redshift (high-z), star-forming galaxies (SFGs). Therefore, their study offer a unique opportunity to study at high linear resolution and signal-to-noise (S/N) extreme star forming events and compare these events with those observed at high-z. Aims. Our goal is to analyze in detail the kinematics of the ionized gas as traced by the Hα emission of a large sample of 38 local (z < 0.1) (U)LIRG systems (50 individual galaxies). In this study, we apply kinematic criteria, which are able to characterize the evolutionary status of these systems, allowing us to derive the disk and merger ratio in such local systems. Methods. We obtained Very Large Telescope (VLT) VIMOS optical integral field spectroscopy (IFS) data of a sample of 38 (U)LIRGs. These systems are morphologically classified in four groups according to their dynamical phases: isolated disk, paired disk, ongoing merger, and post-coalescence merger. The first two are referred as “disk”, while the second two are referred to as “merger”. The “unweighted” and “weighted” kinemetry-based methods are used to kinematically classify our galaxies in disk and merger. The total kinematic asymmetry value Ktot has been used to quantify the global kinematic asymmetry degree of the observed and simulated systems. Results. From the kinemetry-based analysis we are able classify our local (U)LIRGs in three distinct kinematic groups according to their total kinematic asymmetry values (Ktot) as derived when using the weighted (unweighted) method: (1) 25 out of 50 galaxies are kinematically classified as disk with a Ktot ≤ 0.16 (0.14); (2) 9 out of 50 galaxies are kinematically classified as merger with a Ktot ≥ 0.94 (0.66); (3) 16 out of 50 galaxies lie in the “transition region”, in which disks and mergers coexist, with 0.16 (0.14) < Ktot < 0.94 (0.66). The Ktot frontier value that better classifies the highest numbers of disks and mergers, in agreement with their morphology, is Ktot = 0.19 (~0.15): using this value the fractions of “well-classified disks” (Idisk) vs. “well classified mergers” (Imerger) are, respectively, ~80% vs. ~100%. The same results are obtained if we only consider the isolated disks as “true disks”. When we apply our criteria to the high-z simulated systems, a lower total kinematic asymmetry frontier value (Ktot ~ 0.16 (~0.14)) is derived with respect to that found locally. The loss of angular resolution smears out the kinematic features, thus making objects to appear more kinematically regular (disky) than actually they are

The Transcriptomic Analysis of Circulating Immune Cells in a Celiac Family Unveils Further Insights Into Disease Pathogenesis

Celiac disease (CD), the most common chronic enteropathy worldwide, is triggered and sustained by a dysregulated immune response to dietary gluten in genetically susceptible individuals. Up to date either the role of environmental factors and the pathways leading to mucosal damage have been only partially unraveled. Therefore, we seized the unique opportunity to study a naturally-occurring experimental model of a family composed of both parents suffering from CD (one on a gluten-free diet) and two non-celiac daughters. The control group consisted in four unrelated cases, two celiac and two non-celiac subjects, all matching with family members for both disease status and genetic susceptibility. In this privileged setting, we sought to investigate gene expression in peripheral blood mononuclear cells (PBMCs), a population known to mirror the immune response state within the gut. To this purpose, PBMCs were obtained from the four biopsied-proven CD patients and the four non-celiac cases. Each group included two family members and two unrelated control subjects. After RNA purification and cDNA synthesis, each sample underwent a microarray screen on a whole-transcriptome scale, and the hybridization results were visualized by hierarchical clustering. Differentially expressed genes (DEG) were partitioned into clusters displaying comparable regulations among samples. These clusters were subjected to both functional and pathway analysis by using the Kyoto Encyclopedia of Genes and Genomes. Interestingly, on a global gene expression level, the family members clustered together, regardless of their disease status. A relevant fraction of DEG belonged to a limited number of pathways, and could be differentiated based on disease status: active CD vs. treated CD and CD vs. controls. These pathways were mainly involved in immune function regulation, cell-cell junctions, protein targeting and degradation, exosome trafficking, and signal transduction. Worth of noting, a small group of genes mapping on the male-specific region of the Y chromosome, and previously linked to cardiovascular risk, was found to be strongly upregulated in the active CD case belonging to the family, who suddenly died of a heart attack. Our results provide novel information on CD pathogenesis and may be useful in identifying new therapeutic tools and risk factors associated with this condition

Long-Term Clinical Outcome in Systemic Lupus Erythematosus Patients Followed for More Than 20 Years: The Milan Systemic Lupus Erythematosus Consortium (SMiLE) Cohort

Tackling active disease to prevent damage accrual constitutes a major goal in the management of patients with systemic lupus erythematosus (SLE). Patients with early onset disease or in the early phase of the disease course are at increased risk of developing severe manifestations and subsequent damage accrual, while less is known about the course of the disease in the long term. To address this issue, we performed a multicentre retrospective observational study focused on patients living with SLE for at least 20 years and determined their disease status at 15 and 20 years after onset and at their last clinical evaluation. Disease activity was measured through the British Isles Lupus Assessment Group (BILAG) tool and late flares were defined as worsening in one or more BILAG domains after 20 years of disease. Remission was classified according to attainment of lupus low-disease-activity state (LLDAS) criteria or the Definitions Of Remission In SLE (DORIS) parameters. Damage was quantitated through the Systemic Lupus Erythematosus International Collaborating Clinics/American College of Rheumatology damage index (SLICC/ACR-DI). LLAS/DORIS remission prevalence steadily increased over time. In total, 84 patients had a late flare and 88 had late damage accrual. Lack of LLDAS/DORIS remission status at the 20 year timepoint (p = 0.0026 and p = 0.0337, respectively), prednisone dose &ge; 7.5 mg (p = 9.17 &times; 10&minus;5) or active serology (either dsDNA binding, low complement or both; p = 0.001) were all associated with increased late flare risk. Late flares, in turn, heralded the development of late damage (p = 2.7 &times; 10&minus;5). These data suggest that patients with longstanding SLE are frequently in remission but still at risk of disease flares and eventual damage accrual, suggesting the need for tailored monitoring and therapeutic approaches aiming at effective immunomodulation besides immunosuppression, at least by means of steroids

Efficacy and Safety of Anti-SARS-CoV-2 Antiviral Agents and Monoclonal Antibodies in Patients with SLE: A Case-Control Study

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related disease (COVID-19) has spread pandemically with high rates of morbidity and mortality. COVID-19 has also posed unprecedented challenges in terms of rapid development of pharmacological countermeasures to prevent or contrast SARS-CoV-2 pathogenicity. Anti-SARS-CoV-2 antiviral agents and monoclonal antibodies have been specifically designed to attenuate COVID-19 morbidity and prevent mortality in vulnerable subjects, such as patients with immune-mediated diseases, but evidence for the safe and effective use of these drugs in this latter population group is scarce. Therefore, we designed a retrospective, multicentre, observational, case-control study to analyse the impact of these treatments in COVID-19 patients with systemic lupus erythematosus (SLE), a paradigmatic, multi-organ autoimmune disease. We identified 21 subjects treated with antivirals and/or monoclonal antibodies who were matched with 42 untreated patients by age, sex, SLE extension and duration. Treated patients had higher baseline SLE disease activity index 2000 scores [SLEDAI-2K median (interquartile range) = 4 (1–5) vs. 0 (0–2); p = 0.009], higher prednisone doses [5 (0–10) mg vs. 0 (0–3) mg; p = 0.002], and more severe COVID-19 symptoms by a five-point World Health Organisation-endorsed analogue scale [1 (0–1) vs. 0 (0–1); p < 0.010] compared to untreated patients. There was no difference between groups in terms of COVID-19 outcomes and sequelae, nor in terms of post-COVID-19 SLE exacerbations. Three subjects reported mild adverse events (two with monoclonal antibodies, one with nirmatrelvir/ritonavir). These data suggest that anti-SARS-CoV-2 antivirals and monoclonal antibodies might be safely and effectively used in patients with SLE, especially with active disease and more severe COVID-19 symptoms at presentation